Abhilasha A. Lal

Survey of Purple Blotch Disease of Onion (Alternaria porri) of Allahabad District

Onion (Allium cepa) belongs to family Alliaceae and genus Allium with about 300 species. Onion is one of the potential foreign exchange earners for a country like India, as it is second largest producer of onions after China. It contributes 19.25 % of total world production (FAO, 2012). Though India ranks first in terms of the area under onion cultivation in the world and second in its production. It is one of the important ingredients of the daily diet facilitating a constant year round consumer demand. The productivity is still quite low as compared to other countries Anonymous, (2015). Onion crop is attacked by bacteria, fungi, nematodes, viruses, phytoplasma, phanerogamic plant parasite and many other miscellaneous diseases and disorder. Among these diseases, the purple blotch (A. porri) is one of the major constrains in onion cultivation. The pathogen is polyphagus infecting crop like onion, garlic, shallot and other Allium crops. High relative humidity (80 to 90%) and optimum temperature (24+2°C) are needed for further development of purple blotch disease symptoms causing considerable yield losses and is seed borne pathogen causing up to 2060 percent loss in bulb yield and extent of loss depends on time of infection and stage of crop growth. Shahanaz et al., (2007) reported losses of about 50 to 100 per cent with relative occurrence of A. porri. Typical symptoms of the disease appears on foliage and on foliage sheath small white sunken spots develop on International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 10 (2018) Journal homepage: http://www.ijcmas.com

Genetic variability of strains of Verticillium fungicola causing dry bubble disease of white Button Mushroom Agaricus bisporus (Lange) Imbach

The dry bubble caused by Verticillium fungicola, is an important fungal disease of white button mushroom (Agaricus bisporus). Eleven isolates of V. fungicola were collected from six states of North India in 2016. Molecular analyses based on RAPD was used to study the phylogenetic variations among the isolates of V. fungicola. Analysis of RAPD data was performed using five RAPD primers to evaluate the genetic variability. The result analysis showed that the genetic variability of the isolates was low and they were almost clonal. Relative correlations between geographical origins of isolates and molecular grouping were observed but there was no correlation between virulence assays and RAPD patterns.

Effect of organic and inorganic salts against sour rot (Geotrichum candidum) of Tomato

Carbendazim and nine selected organic and inorganic salt compounds, considered as common food additives, were evaluated for their activity against Geotrichum candidum, causal agent of tomato sour rot. The maximum inhibition of mycelial growth were recorded in carbendazim (82.9%) followed by sodium carbonate (43.9%), while minimum inhibition was recorded in magnesium sulphate (6.0%) as compared to control. Carbendazim was found most effective and five salts in vitro were tested in vivo. All tested salt compounds significantly reduced the disease severity. The lowest disease severity was recorded in treatment of carbendazim (63.6%) followed by sodium carbonate (73.8%) and highest disease severity was recorded in sodium thiosulphate (83.5%) as compared to control (100%). Physiological loss in weight was minimum in carbendazim (2.3%) and calcium carbonate (3.0%), as compared to control (8.0%). Highest lycopene content of tomato was obtained in sodium carbonate (5.04 mg/100g) followed by boric acid (4.49 mg/100g), as compared to control (5.05 mg/100g).